Method and apparatus for improving heat transfer and reaction efficiency of gas hydrate reactor using scraper

Abstract

The present invention relates to an apparatus comprising a reactor body to which gas and water are supplied to create a gas hydrate; an upper cover which is engaged to an upper portion of the reactor body, a scraper mounted rotationally within the reactor body, and a motor for providing a driving force to the scraper. It is possible to remove gas hydrate particles attached to at least one of an inner surface of the reactor body and an inner surface of the upper cover, by a rotary driving of the scraper. According to the invention, it is possible to prevent a material hindering a heat transfer by attaching on a wall surface of the reactor, through a process of scraping out gas hydrate particles, when the scraper which is rotationally driven about a center axis of the reactor is close to the inner surface of the reactor.

Claims

1. A method comprising: supplying gas and water to a reactor body in which gas hydrates are created; applying a driving force to rotate a scraper assembly which is arranged for rotation within the reactor body by using a scraper driving motor; actuating a stirring apparatus at a different speed from a rotating speed of the scraper assembly by a speed reducer arranged to surround a rotating bar of the scraper assembly; and removing gas hydrate particles attached onto an inner surface of the reactor body and an upper cover engaged to the reactor body, by a rotational movement of the scraper assembly relative to the inner surface of the reactor body and the upper cover, wherein the scraper assembly operates to perform a stirring function, wherein the stirring apparatus is actuated under a condition with the same center of rotation as the scraper, and wherein the scraper assembly includes: the rotating bar; a first scraper for scraping the inner surface of the reactor body, the first scraper connected to the rotating bar; and a second scraper for scraping the inner surface of the upper cover, the second scraper connected to the rotating bar.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a schematic diagram of a typical gas hydrate producing apparatus according to a prior art.

(2) FIG. 2 is a perspective view of a typical gas hydrate producing apparatus according to a prior art.

(3) FIG. 3 is an exploded perspective view of a scraper arranged at the inside of a reactor according to an embodiment of the present invention.

(4) FIG. 4 is a partly enlarged view of FIG. 3, showing an upper structure of the scraper in detail.

(5) FIG. 5 is a top plan view showing the inside of the reactor.

(6) FIG. 6 is a graph showing a temperature change and a production rate of hydrate when the hydrate is deposited on an inner surface of an existing reactor body in a prior art.

(7) FIG. 7 is a graph showing a temperature change and a production rate of hydrate when the scraper is incorporated according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(8) Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numerals refer to like parts throughout the various figures and embodiments of the present invention.

(9) Water treatment method utilizing a plurality of guest gases according to an embodiment of a present invention will now be explained in detail in connection with the accompanying drawings.

(10) Hereinafter, the term gas means a guest gas of a gas hydrate, while the term water means a host molecule. In a generation of the gas hydrate, molecules which can be referred to as the guest gas include, for example, CH.sub.4, C.sub.2H.sub.6, C.sub.3H.sub.8, CO.sub.2, H.sub.2, SF.sub.6 and the guest gas and water (H.sub.2O) are referred to as the gas and the host molecule, respectively.

(11) Construction of a Gas Hydrate Reactor Having a Scraper

(12) Firstly, the gas hydrate reactor having a scraper according to an embodiment of a present invention will be described in connection with FIGS. 1 to 5.

(13) The gas hydrate reactor 100, according to the present invention, includes a supplying source, a temperature sensor and a pressure sensor which are provided on the reactor, the supplying source and a tank, respectively, which are connected to a controller so that these can be controlled, but the description of elements such as the supplying source, the tank, sensors and the controller will be omitted, for simplification.

(14) Likewise, a control unit to input operation parameters by user and to control an operation of the gas hydrate reactor 100 may be connected to the controller, but the description of these elements will also be omitted, for simplification.

(15) Also, the gas hydrate reactor 100 according to an embodiment of a present invention is shown in the drawings, but it is to be understood that there is no intention to limit the invention to the forms such as a position, an arrangement, or a connecting method in the respective constructing elements.

(16) The gas hydrate reactor 100 comprises a cylinder-shaped reactor body 110, an upper cover 120 which is engaged to an upper portion of the reactor body so that it can be opened and closed, a scraper 130 which is rotationally driven about a center axis of the reactor body 110, a stirring apparatus 140 configured to be driven under a condition forming the same center of rotation as the scraper 130, a scraper driving motor for providing a driving force, and a propeller driving motor 160 for providing a driving force to a propeller structure 170 disposed on a lower portion of the reactor body 110. Here, the reactor body 110 has a support 101 disposed on the lower portion of the reactor body 110 at a predetermined distance so that the support 101 can be stably positioned on the ground.

(17) In the gas hydrate reactor 100, water and gas are supplied from an external supplying source (not shown) into the reactor body 110, and then the gas hydrate is created by an reaction between the water and the gas, by a rotational driving of the scraper 130 and the propeller structure 170. A gas hydrate slurry created at the reactor body 110 is discharged from the gas hydrate reactor 100 through a slurry outlet 122 connected to the upper cover 120, and the discharged gas hydrate slurry is palletized by way of, for example, a dewatering process, a cleaning process, a compression process, etc. or a dissociation process, for example, may be added, so that a desalination process can be performed.

(18) It is possible to use the reactor body 110 not only as a reactor that the water and the gas react to each other, but as a dehydrator and a storage tank. That is, after the gas hydrate is formed, dewatering and storage processes may be separately performed or may be implemented by a single process so that a number of processes can be implemented in a single space.

(19) The upper cover 120, having a lid-type open/close construction, has one side which is coupled with an upper part of the reactor body 110 by a clamping operation to facilitate an open/close operation of the reactor body 110.

(20) The scraper 130 includes a rotating axis 131 disposed on a center axis of the reactor body 110, a first scraper 132 for removing the gas hydrate particles attached to an inner surface of the reactor body in such a manner that it is connected to the rotating axis 131, and a second scraper for removing the gas hydrate particles attached to an inner surface of the upper cover 120 in such a manner that it is connected to an upper portion of the rotating axis 131. The first scraper 132 consists of a plurality of components that can be arranged in a line at predetermined intervals.

(21) The first scraper 132 is equipped with a first blade 134 for sliding along the inner peripheral surface of the reactor body 110, and a first connecting bar 133 for connecting the rotating axis 131 to the first blade 134. Likewise, the second scraper 135 is equipped with a second blade 137 for sliding along an inner peripheral surface of the upper cover 120, and a second connecting bar 136 for connecting the rotating axis 131 to the second blade 137. Here, these connecting bars 133 and 136 also function to help a mixing of materials within the reactor body 110 through a predetermined rotation process.

(22) The first blade 134 is preferably designed to have a predetermined radius of curvature so that it is close to the inner surface of the reactor body 110. Similarly, the second blade 137 is preferably designed to have a predetermined radius of curvature so that it is close to the inner surface of the upper cover 120.

(23) A stirring apparatus or agitator 140 can be extended circumferentially to a speed reducer 141 coupled to surround the rotating axis 131. The stirring apparatus 140 is rotationally driven about the rotating axis 131 which is actuated by a scraper driving motor 150, in which the speed reducer 141 controls a rotational speed of the rotating axis 131 and sends it to the stirring apparatus 140, so that the rotational speed of the stirring apparatus 140 can be maintained at a low speed, compared to the rotational speed of the scraper 130.

(24) When a propeller structure 170 is disposed on the lower portion of the reactor body 110, it is possible to supply the water and the gas entering the reactor body 110 in such a manner that the water and the gas are properly mixed. That is, a separate propeller driving motor 160 provides rotary power to the propeller structure 170 so that reacting materials supplied from a lower portion of the reactor body 110 can be quickly diffused at a faster speed.

(25) As mentioned above, according to the present invention, the scraper 130 and the stirring apparatus 140 may be operated simultaneously by a rotary driving or may be rotated at a speed different to each other by the speed reducer 141. Thus, the scraper 130 is capable of removing the gas hydrate particles which may be attached to the inner surface of the reactor 100 while performing effectively a stirring action of the water and the gas which are received in the reactor 10, so that an environment for promoting the gas hydrate forming reaction can be established.

(26) It is thus apparent that a system using the scraper according to the present invention is definitely superior to the prior art by enhancing the production rate of the hydrate, and the reason will be described.

(27) FIG. 6 illustrates that the gas hydrate is deposited within the reactor body with a thickness of about 5 mm, and FIG. 7 illustrates that the gas hydrate is not deposited within the reactor body by incorporating the scraper according to the present invention

(28) In view of a cooling efficiency, in the case of FIG. 6 showing that the gas hydrate is deposited in a thickness of about 5 mm, there is no substantial difference between an inlet temperature and an outlet temperature of a cooling water due to lowering of the cooling efficiency, but, in the case of FIG. 7 showing that the gas hydrate is not deposited, it is apparent that the outlet temperature of the cooling water is remarkably increased compared to the inlet temperature, so that a thermal transfer through a wall surface of the reactor body can be actively performed. Moreover, in order to cause a reaction based upon the prior art, it is necessary to supply a cooling water having a much lower temperature than a condition shown in FIG. 7, but this would in turn cause an undesirable increase of the energy cost for cooling and the installation cost.

(29) Also, in view of a reaction rate, in the case of FIG. 7 showing that the gas hydrate is effectively removed, it is apparent that a hydrate production rate is much greater than that shown in FIG. 6, depending upon lowering of a cooling water inlet temperature. Furthermore, also in the case of an inlet temperature condition of the same cooling water, it is observed that hydrate production rate is much greater than that shown in FIG. 6.

(30) Operation of Gas Hydrate Reactor Having Scraper

(31) Hereinafter, an operation of the gas hydrate reactor 100 having a scraper will be explained in connection with FIGS. 1 to 5.

(32) Firstly, water and gas are supplied through the lower portion of the reactor body.

(33) The supplied water and gas are distributed and diffused by a rotating operation of the propeller structure 170 which is activated by the propeller driving motor 160, and is moved towards the upper portion in the reactor body 110.

(34) Particles, attached to the inner surface of the reactor body 110, of gas hydrate slurries produced according to the reaction between water and gas, can be removed by a rotation operation of the scraper 130 which is activated by the scraper driving motor 170. That is, the first blade 134 of the first scraper 132 is slid along the inner peripheral surface of the reactor body 110, so that the attached particles can be separated and removed. Similarly, the second blade 137 of the second scraper 135 is slid along the inner peripheral surface of the upper cover 120, so that the attached particles can be separated and removed.

(35) Meanwhile, a temperature of the reactor body 110 can be measured in real-time by a thermometer 114, which is controlled by a controller (not shown), installed within the reactor body 110, and thus it is possible to check whether or not the temperature is in the range of a proper condition for a production of gas hydrate.

(36) A see-through window 112 which is provided within the reactor body 110 is oval in shape, through which it is possible to view with the eye as to whether or not the reaction during the gas hydrate production process is properly implemented.

(37) When the scraper 130 is rotationally driven, the stirring apparatus 140 which is rotationally driven about the rotating axis 131, identically with the scraper 130, can be controlled in view of the speed ratio through the speed reducer 141 to be driven at a speed different from the scraper 130. That is, the stirring apparatus 140 is rotationally driven about the rotating axis 131 which is actuated by the scraper driving motor 150, in which the speed reducer 141 controls a rotational speed of the rotating axis 131 and sends it to the agitator 140, so that the rotating speed of the speed reducer 141 can be maintained at a low speed, compared to the rotational speed of the scraper 130.

(38) The gas hydrate slurry produced in the reactor body is discharged from the reactor 100 through the outlet 122 coupled with the upper cover 120, and then it can be processed by, for example, palletizing or desalination work, etc. by way of the processes such as dewatering, compression, cleaning, etc.

(39) As mentioned above, according to the gas hydrate reactor having a scraper of the invention, it is possible to remove the gas hydrate particles attachable on the reactor body and the inner surface of the upper cover, by means of the scraper which is rotationally driven about the center axis of the reactor body to which water and gas are supplied from the external supplying source, causing an undesirable production of the gas hydrate. Thus, according to the present invention, since the gas hydrate particles formed in the reactor are not attached on its inner surface, it is possible to prevent lowering of heat transfer through a wall surface of the reactor body.

(40) While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.